The nerves of the enemy

From ‘The progress in Flanders’,
29 September 1917: The fighting has reached a degree of intensity never before known. There is no leisure or rest for any one. The instruments of destruction which fly through the air by day and night are more numerous and more various than before… The strain to which the enemy, even more than ourselves, is subjected is terrific beyond words. We imagine that for one shell that the Germans send over we throw across four, five, or perhaps six. There is also what may be called a kind of camouflage in artillery work, when the drum-fire which the Germans regard as the sure herald of a coming attack culminates in no attack. The nerves of the enemy are, in fact, kept at the breaking-point the whole time.